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kite
05-12-2003, 11:48 AM
Is there any way to get OS X (10.2.6) to show previews of .hdr files?
Or any other way to navigate trough my .hdr files fast?

It's a true pain to go trough all images by loading them into Image Editor.
:(

claw
05-12-2003, 12:21 PM
Sorry, but I dont think so. HdriShop is a HDRI editor for windows, but it never came to mac:(

kite
05-12-2003, 01:35 PM
Is there a way to use HdriShop to create previews for the files?, if such thing exist on the windows platform ;)
Maybe I can export the files back to OS X with the new icons/previews?

Beamtracer
05-12-2003, 03:28 PM
HDR images (32-bit-per-channel) are extremely useful for 3D work, but still not a mainstream thing. Most 'graphic artists' don't know that HDR images exist. That's why programs like Photoshop don't support HDRI. You also can't preview them from the desktop.

Many compositing applications can see HDR images (Shake, Commotion, Combustion).... Adobe After Effects can't.

I guess you already know you can load them up in Lightwave as a backdrop and then render them out to another format for previewing.

Strangely enough, Apple's 'Preview' application (the newest version) seems to be able to load up 16-bit-per-channel Photoshop images, and cut out the image according to the alpha channel. However, this is not 32bpc as you want.

luka
05-13-2003, 12:23 AM
Hey do you think you could edit HDR images with this?

Silverfast (http://www.silverfast.com/img/screenshots/SF-HDR-en.jpg):)

kite
05-13-2003, 04:59 AM
Beamtracer> I dont know much about bits/channels. But I've tried a few hdri tutorials and it looked ok. So now I've collected a bunch of them .hdr and .exr files :)
Isnt .hdr 48bit-per-channel?
I get prewievs of 32bit tif files I save from LW, in OS X (10.2.6) with black background.
I might render each one, a day I have alot of time to spare if thats the only way to do it.

luka> Thanks.
I've tried to import my .hdr- and .exr-files, but SilverfastHDR will not read them.
The problem might be me though :)
Or that I run it in demo-mode.

luka
05-13-2003, 07:33 AM
I think someone was tring to port HDRI SHop to OSX? What was the guys name...? I think he was a lighwave engineer.

Red_Oddity
05-13-2003, 09:17 AM
I think HDRI are floating point....

wizlon
05-13-2003, 10:59 AM
Kenneth Woodruff did a port of - mkhdr (Make HDR) for Mac, it's still in Beta, but you can download it. I think it contains a hdr viewing app.

Beamtracer
05-13-2003, 04:04 PM
Most common image formats are 8-bit-per-channel.

These include the usual JPEG, PNG, Targa, Tiff images.

When you select these images on the render menu in Lightwave, you see them listed as either 24 or 32 bits. This is because the 3 color channels (R+G+B) each have 8 bits, which makes a total of 24. When there is an alpha channel (RGBA) it makes a total of 32 bits, when all the channels are combined.

This is confusing, as HDR images are also 32-bit, but HDR is 32 bits-per-channel. When the HDR image is RGB, then some would describe it as a 96 bit image, or an RGBA 128 bit image.

So you have to keep in mind the difference between the total number of "bits" in an image, as opposed to the number of bits in each channel of the image.

Kenneth Woodruff wrote a tutorial explaining this, and how you can use HDR images. I think it may still be on the Newtek website in the Lightwave tutorial section. It's worth a read if you want to understand HDRI, which every Lightwaver should.

kite
05-13-2003, 04:31 PM
Thanx Beamtracer, I guess I'll have a go at that tutorial.
Need a reason to get away from the InsideLW7 book for a while, that one tend to get just as boring as my homework :D

Red_Oddity
05-14-2003, 02:30 AM
Isn't HDRI floating point? 32bit floating point per channel?

Here's a PDF by the guy who basically invented HDRI at SGI, Greg Ward:
http://www.debevec.org/Research/HDR/Ward-HDRImaging-20010521.pdf

To cut it short:

HDR Radiance RGBE:

8bits each for 3 mantissas and 1 exponent
76 orders of magnitute in 1% steps


Not sure though which format is better though SGI32 LogLuv or Radiance HDRI...hmmm...anyone?

Red_Oddity
05-15-2003, 03:13 AM
BTW...OSX is Unix right...then why don't i see anylinks on a Unix HDRI viewer in here....there's gotta be atleast one right...you can't tell me all research at SGI was done on Irix or x86 machines...

hcoat
05-17-2003, 04:46 AM
There are couple of Unix HDRI viewer out there but running them isn't all that easy. filmgimp will open HDRIs but it wouldn't save in the .HDR format though you can save as a tiff and keep as 32b, but I doesn't creat preview. The other is ximage, it come with radiance which is a reseach 3d application use in the development of the lighting. to run it you'll need X11 and know little Unix. It's free if you want to play with it.

http://radsite.lbl.gov/radiance
http://www.debevec.org/Probes/

bbuxton
05-17-2003, 03:30 PM
Try this
http://viz.cs.berkeley.edu/~gwlarson/pickup/photophile.tar.gz
It allows you to assemble HDR/LogLuv/EXR from a series of 8bit images.

bb

bbuxton
05-17-2003, 03:31 PM
sorry it's Mac OsX
bb

MacDude
05-20-2003, 11:39 AM
kite

If you have loads of HDR images can you not convert them (through Lightwave as a backdrop, rendered and save perhaps) to .jpgs and keep them in the same directory as your HDRs. if they are just for previews so you know what they look like they don't have to be that big either.

Just a thought.

royL
05-20-2003, 02:26 PM
This is a utility for editing HDRI, altough it seems that you cannot save back to hdr, but you can save in other float point (high dynamic)formats, simmilar to hdr that you can use in LW.

http://filmgimp.sourceforge.net/

Beamtracer
05-20-2003, 03:38 PM
I always thought that Mac Film Gimp could only work in 16bpc floating point images, rather than 32bpc.